Experimental Study of the Richtmyer-Meshkov Instability on Inclined Interface

Abstract

The RichtmyerMeshkov instability (RMI) is a hydrodynamic instability resulting from an impulsive acceleration of a density gradient. This instability was first described in the theoretical work of Richtmyer [2], and later in the experimental work of Meshkov [3]. The two primary ingredients for the RMI are an impulsive acceleration which takes the form of an instantaneous pressure gradient, and a fluid interface which generates a density gradient that is misaligned with the pressure gradient. To further our investigation of the RMI an initial condition experiment needed to be conducted. At the Texas A&M Shock Tube and Advanced Mixing Lab (STAML) there is a Mach 3 capable shock tube, used to study the RMI. It was necessary to study the initial conditions of the interface to understand its effects on the development of the RMI at post-shocked times. From this we were able to determine characteristic flow qualities present on the interface prior to the shock. Within the initial conditions investigation was a qualitative study conducted to determine the vorticity of the interface. The vorticity study was to show how much energy the shock wave deposits, and aid in development of a controlled perturbation of the interface. In the case of the qualitative vorticity study, little was learned due to problems encountered involving Particle Image Velocimetry (PIV) imaging. However, a method for controlled perturbation techniques was discovered involving the flow characteristics at the interface.